Editing Soviet atomic bomb project (section)

=== Chagan ===

[[Chagan (nuclear test)|Chagan]] was a shot in the [[Nuclear Explosions for the National Economy]] (also known as Project 7), the Soviet equivalent of the US ''[[Operation Plowshare]]'' to investigate [[Peaceful nuclear explosions|peaceful uses of nuclear weapons]]. It was a subsurface detonation. It was fired on January 15, 1965. The site was a dry bed of the river [[Chagan River (tributary of Irtysh River)|Chagan]] at the edge of the [[Semipalatinsk Test Site]], and was chosen such that the lip of the crater would dam the river during its high spring flow. The resultant crater had a diameter of 408 meters and was 100 meters deep. A major lake (10,000&nbsp;m<sup>3</sup>) soon formed behind the 20–35&nbsp;m high upraised lip, known as ''[[Chagan Lake (Kazakhstan)|Chagan Lake]]'' or ''Balapan Lake''.{{Citation needed|date=March 2008}}

The photo is sometimes confused with [[RDS-1]] in literature.